Helleborus plant named ‘COSEH 770’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘COSEH 770’, characterized by its upright and mounding plant habit; uniform and freely flowering habit; dark green-colored leaves; long flowering period; single light green-colored flowers; and good garden performance.

Botanical designation: Helleborus×nigercors.

Cultivar denomination: ‘COSEH 770’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofHelleborus plant, botanically known as Helleborus×nigercors, andhereinafter referred to by the name ‘COSEH 770’.

The new Helleborus plant is a product of a planned breeding program inGlandorf, Germany. The objective of the breeding program was to createnew uniform Helleborus plants with unique and attractive leaf and flowercoloration and resistance to pests.

The new Helleborus plant originated from a cross-pollination conductedby the Inventor in Glandorf, Germany in November, 2002 of two unnamedproprietary seedling selections of Helleborus×nigercors, not patented.The new Helleborus plant was discovered and selected by the Inventor asa single flowering plant from within the progeny of the statedcross-pollination grown in a controlled greenhouse environment inGlandorf, Germany in February, 2005.

Asexual reproduction of the new Helleborus plant by divisions in acontrolled greenhouse environment in Glandorf, Germany since March,2005, has shown that the unique features of this new Helleborus plantare stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in cultural practices and environmental conditions such astemperature and light intensity without, however, any variance ingenotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of the Helleborus ‘COSEH 770’. Thesecharacteristics in combination distinguish the Helleborus ‘COSEH 770’ asa new and distinct Helleborus plant:

-   -   1. Upright and mounding plant habit.    -   2. Uniform and freely flowering habit.    -   3. Dark green-colored leaves.    -   4. Long flowering period.    -   5. Single light green-colored flowers.    -   6. Good garden performance.

Compared to plants of the parent selections, plants of the newHelleborus flower more freely and more uniformly.

Plants of the new Helleborus can be compared to plants of Helleborusniger×Helleborus lividus ‘COSEH 700’, disclosed in U.S. Plant Pat. No.21,003. Plants of the new Helleborus differ primarily from plants of‘COSEH 700’ in the following characteristics:

-   -   1. Plants of the new Helleborus have lighter green-colored        leaves than plants of ‘COSEH 700’.    -   2. Plants of the new Helleborus and ‘COSEH 700’ differ in flower        color.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new Helleborus plant and show the colors as true as it isreasonably possible to obtain in colored reproductions of this type.

Colors in the photographs may differ slightly from the color valuescited in the detailed botanical description which accurately describethe colors of the new Helleborus plant.

The photograph on the first sheet comprises a side perspective view of atypical flowering plant of ‘COSEH 770’ grown in a container.

The photograph on the second sheet is a close-up view of a typicalflower of ‘COSEH 770’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurementsand values describe plants grown during the winter in two-litercontainers in a glass-covered greenhouse in Glandorf, Germany and underconditions which closely approximate commercial Helleborus production.During the production of the plants, day temperatures ranged from 12° C.to 32° C. and night temperatures ranged from 3° C. to 18° C. Plants wereone year old when the photographs and the description were taken. In thefollowing description, color references are made to The RoyalHorticultural Society Colour Chart, 2007 Edition, except where generalterms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus×nigercors ‘COSEH 770’.-   Parentage:    -   -   Female, or seed, parent.—Unnamed proprietary seedling            selection of Helleborus×nigercors, not patented.        -   Male, or pollen, parent.—Unnamed proprietary seedling            selection of Helleborus×nigercors, not patented.-   Propagation:    -   -   Type.—By tissue culture.        -   Time to initiate roots.—About two months at 12° C.        -   Time to produce a rooted young plant.—About six months at            4° C. to 15° C.        -   Root description.—Thick to thin, fleshy; white to brown in            color.        -   Rooting habit.—Sparse.-   Plant description:    -   -   Plant form and growth habit.—Herbaceous perennial; upright            and mounding plant habit with flowers held above the foliar            plane; shape, globular; moderately vigorous growth habit.        -   Plant height.—About 31.7 cm.        -   Plant diameter (area of spread).—About 55.1 cm.-   Foliage description:    -   -   Arrangement.—Leaves arranged in a basal rosette; leaves            palmately compound with five leaflets per leaf.        -   Leaf length.—About 19.6 cm.        -   Leaf width.—About 19.6 cm.        -   Leaflet length.—About 12.1 cm.        -   Leaflet width.—About 5 cm.        -   Leaf shape.—Palmate; orbicular in outline.        -   Leaflet shape.—Elliptic to ovate; lower leaves occasionally            cleft.        -   Leaflet apex.—Acute.        -   Leaflet base.—Attenuate.        -   Leaflet margin.—Sharply senate.        -   Leaflet texture, upper and lower surfaces.—Smooth, glabrous;            leathery.        -   Leaflet venation pattern.—Pinnate.        -   Leaflet color.—Developing leaves, upper surface: Close to            137A. Developing leaves, lower surface: Close to 146A to            146B. Fully developed leaves, upper surface: Between N137A            and 147A and towards the base, close to 166A, venation,            close to 144A. Fully developed leaves, lower surface:            Between 137D and 147B; venation, between 144C and 145A.        -   Petiole.—Length: About 14.2 cm. Diameter: About 6 mm.            Texture, upper and lower surfaces: Smooth, glabrous. Color,            upper and lower surfaces: Between 143B and 144A and base,            close to 177B to 177C.-   Flower description:    -   -   Flower shape and habit.—Single rotate flowers arranged on            terminal cymes; freely and uniform flowering habit with            about 100 flowers and flower buds per plant; flowers facing            outwardly to slightly nodding and slightly upright.        -   Fragrance.—None detected.        -   Natural flowering season.—Long flowering period; plants            flower from late winter to early spring in Germany.        -   Flower longevity on the plant.—About ten days; flowers not            persistent.        -   Flower buds.—Length: About 1.9 cm. Diameter: About 1.3 cm.            Shape: Ovate. Color: Close to 145C.        -   Inflorescence height.—About 22.5 cm.        -   Inflorescence diameter.—About 31.5 cm.        -   Flower diameter.—About 7.6 cm.        -   Flower depth (height).—About 2.7 cm.        -   Petals.—Transformed into nectaries.        -   Sepals.—Arrangement: About five in a single whorl. Length:            About 3.8 cm. Width: About 2.8 cm. Shape: Broadly elliptic            to broadly obovate. Apex: Rounded. Margin: Entire. Texture,            upper and lower surfaces: Smooth, glabrous. Color: When            opening, upper surface: Close to 145C, towards the base,            close to 145A to 145B and towards the apex, close to 145D.            When opening, lower surface: Close to 145B, towards the            base, close to 145A and towards the apex, close to 145C.            Fully opened, upper surface: Close to 150D and towards the            base, close to 145A; with development, color becoming closer            to 146B to 146C. Fully opened, lower surface: Between 145C            and 150D and towards the base, close to 145A.        -   Peduncles.—Strength: Moderately strong. Length: About            9.2 cm. Diameter: About 7 mm. Aspect: About 15° from            vertical. Texture: Smooth, glabrous. Color: Close to 144C.        -   Pedicels.—Strength: Moderately strong. Length: About 2.5 cm.            Diameter: About 2.5 mm. Aspect: About 20° from the peduncle            axis. Texture: Smooth, glabrous. Color: Close to 144C.        -   Reproductive organs.—Stamens: Quantity per flower: About 70.            Filament length: About 1.4 cm. Filament color: Close to            157D. Anther shape: Narrowly reniform. Anther length: About            2 mm. Anther color: Close to 150B. Pollen amount: Moderate.            Pollen color: Close to 158D. Pistils: Quantity per flower:            About five. Pistil length: About 1.25 cm. Stigma shape:            Club-shaped. Stigma color: Close to 150C to 150D. Style            length: About 1.2 cm. Style color: Close to 150C. Ovary            color: Close to 145A. Nectaries (transformed petals):            Quantity per flower: About 15. Length: About 8 mm. Diameter,            apex: Close to 2 mm. Diameter, base: Close to 1 mm. Shape:            Flattened triangular. Color: Close to 145A and towards the            apex, close to 150B.        -   Seeds/fruits.—Seed and fruit development have not been            observed.-   Garden performance: Plants of the new Helleborus have been observed    to have good garden performance and to tolerate rain, wind and    temperatures ranging from about −10° C. to about 35° C.-   Pathogen/pest resistance: Plants of the new Helleborus have not been    shown to be resistant to pathogens and pests common to Helleborus.

1. A new and distinct Helleborus plant named ‘COSEH 770’ as illustratedand described.